WHAT’S UP DOC? Retina hole

Tuesday

Jul 11, 2017 at 5:44 PMJul 11, 2017 at 5:44 PM

By Dr. Jeff Hersh/Daily News Correspondent

Q: After my yearly eye exam my doctor told me I had a hole in my retina. How did I get this?

A: Light enters the eye, is focused by the lens, then travels through a clear gel-like substance (the vitreous humor which fills the eye and maintains its shape) to land on the light-sensitive retina (the “screen” in the back of the eye). The retina contains the photoreceptors (rods and cones) that create electrical signals that travel through the optic nerve to the brain. These electrical signals are interpreted by the brain as our sense of vision.

The 100 million rods that are located all over the retina are sensitive to very low levels of light, but only transmit signals that differentiate black and white. The 6 million cones (which come in three ‘color’ varieties of red, green and blue) require more light to be activated, but help differentiate colors. The macula is the center area of the retina where there is the highest density of cones; it provides the sharpest and most detailed signals from the center visual field to the brain, allowing us to see fine detail.

The retina is held in place by an underlying support structure, acting like the theatre wall that supports a movie screen. The vitreous humor has multiple fiber-like structures that anchor in the retina.

Shrinkage of the vitreous humor is a normal part of aging, and the volume loss is normally replaced by other fluids. If the vitreous shrinkage occurs in a way where its retinal connections exert too much force, it may lift the retina. If the retina itself is firmly attached to its anchoring structures at that point, this pull-pull in opposite directions can result in a tear, creating a retinal hole.

The major risk factor for developing a retinal hole is age over 60. Women are more likely to develop this condition than men. Other risk factors include nearsightedness, trauma, and rarely other conditions. A person who has had a retinal hole in one eye has a 10 percent lifetime chance of developing a retinal hole in their other eye.

The symptoms, prognosis and treatment of a retinal hole depends on its size, depth and location of the tear. Retinal holes are often diagnosed during a routine ophthalmological examination by an eyecare professional who uses specialized devices to visualize the retina in detail.

A retinal hole may disrupt vision from the affected area, hence macula holes will have more severe visual loss than a similar size/depth hole elsewhere in the retina. Many peripheral retinal holes do not cause any noticeable symptoms, but others may cause visual ‘floaters’ (streaky areas of blurry/distorted vision, although these may also occur as a normal part of the eye’s aging process), and even severe central visual blurriness (if a large part of the macula is affected).

The decision of if, when and how to treat a retinal hole is made on a patient by patient basis, and depends on the risk of progression or complications developing. Deeper/larger holes have an increased risk of getting progressively bigger. They may allow some of the eye’s fluid to get behind the retina, lifting it away from its supporting structure and even allowing it to detach (retinal detachment), a concerning possible complication which can cause blindness.

The most common treatment approach is a vitrectomy. In this surgical procedure the vitreous humor is removed (to prevent it from further pulling on the retina) and replaced by a clear fluid containing special bubbles. For at least two days, and up to two weeks, after the surgery the patient must remain predominately in a face-down position. This causes the bubbles to float to the back of the eye and push on the retina, holding it in place to allow it to re-adhere as it heals. The bubbles will be reabsorbed over weeks, and completely reabsorbed over a period of months.

Overall, a vitrectomy resolves the retinal tear in up to 90 percent of treated patients. However, a cataract sometimes forms as a complication of this procedure. If this cataract becomes severe enough it may require cataract surgery. Less commonly an infection or a retinal detachment may occur as a vitrectomy complication, and if so these need to be treated.

Other treatments can possibly seal a retinal tear; these include laser photocoagulation, cryopexy, diathermy and others. Use of these depends on the specifics of the patient’s condition and other factors.

When a retinal hole is diagnosed early, the prognosis for a successful outcome is quite good. So, be sure to get the regular eye checkups that are recommended for you.